#67 - Printings Past

The evolution of printing technology is an interesting one. In the beginning we had these wonderful printers that were just glorified automatic typewriter. Then came the dot matrix printers.

Dot Matrix printers have a print head that runs back and forth on the page and prints by impact, striking an ink-soaked cloth ribbon against the paper, much like a typewriter. Unlike a typewriter or daisy wheel printer, letters were created out of a matrix of dots, and thus, varied fonts and arbitrary graphics can be produced. Because the printing involves mechanical pressure, these printers can create carbon copies (you remember them?). Paper was pulled through the the machine over a roller just like a typewriter. Rods formed the matrix and would hit a ribbon to produce the type. The first Dot Matrix printer appeared in 1970 from Digital Equipment Corporation.

A thermal printer produces a printed image by selectively heating coated thermochromic paper. When the paper passes over the thermal print head. The coating turns black in the areas where it is heated, producing an image similar to the dot matrix printers. Thermal printers are still used today in small printers like label printers and receipt printers.

Ink Jet printers were invented at Hewlett Packard in 1979. The first in jet printers were based on thermal technology. This printing technique heats ink, creating tiny bubbles that squirt ink onto paper when they burst. By 1984, HP had released the ThinkJet—the first low-cost, mass-produced inkjet printer that offered a disposable cartridge for monochrome printing. Over time, HP refined cartridge body designs and ink delivery systems to make color printing possible. The first generation of color inkjet printers used dye-based inks. Later generations used pigment-based inks that enhanced water—and light-fastness—enabling outdoor signage and other applications.

Laser Printers were invented separately by IBM and Xerox. The first commercial laser printer was the IBM 3800 Printer in 1975. It was big as a car and cost in the 6 figures. In 1984, HP introduced the LaserJet, the first desktop laser printer, which rapidly became a huge success due to its modest $3,000 price tag. The technology in laser printing is essentially that of the copier. The laser is used in imprinting the image on a drum that transfers the image via toner dust thermally to the paper.